Merge pull request #572 from ofthesun9/1.5-alpine_3.8

alpine 3.8 for nginx front container

core/nginx/Dockerfile

@@ -1,6 +1,9 @@
-FROM alpine:3.7
+FROM alpine:3.8
 
 RUN apk add --no-cache nginx nginx-mod-mail python py-jinja2 certbot openssl
+# added to fix #522
+RUN apk add --no-cache py-requests-toolbelt py-pip
+RUN pip install "idna<2.7"
 
 COPY conf /conf
 COPY *.py /